1. Field of the Invention
The present invention relates to a process for producing alicyclic hydrazine derivatives, tetrahydropyridazine and hexahydropyridazine which are useful as intermediate starting materials such as medicines and agricultural chemicals.
2. Description of Prior Art
The present inventors proposed a method for producing tert-butylhydrazine hydrohalogenic acid salt by reacting hydrazine hydrohalogenic acid salt and tert-butanol which are industrially or economically advantageous starting materials (Japanese Patent Publication No. 48823/1986) equivalent to U.S. Pat. No. 4,435,600, issued Mar. 6, 1984 on an application filed Mar. 10, 1983.
However, it has not yet been known that a difunctional alcohol (diol) or an alicyclic ether compound reacts with a hydrazine hydrohalogenic acid salt to give an alicyclic hydrazine derivative hydrohalogenic acid salt.
As a method for producing an alicyclic hydrazine derivative or its hydrohalogenic acid salt, there are known a method of reacting an alkyl dihalide with hydrazine hydrate [USSR Pat. 87-4337106], [J. Am.Chem. Soc. 88, 3959-3963 (1966)] (prior art 1), and a method of synthesizing alicyclic hydrazine by using an alicyclic amine as a starting material [U.S. Pat. No. 3,317,607] (prior art 2).
However, the prior art 1 relating to a method of producing an alicyclic hydrazine derivative or its hydrohalogenic acid salt has a problem that an economically expensive dihalogenobutane is required as a starting material. Furthermore, the prior art 2 is a general method of synthesizing alicyclic hydrazine, but the stability and toxicity of the nitroso body which is an intermediate pose a problem.
On the other hand, a known conventional method of synthesizing hexahydropyridazine includes reacting a hydrazine dicarboxylic derivative with a dihalogenobutane to obtain hexahydropyridazine-1,2-dicarboxylic derivative, and further decarboxylating the resulting product to give an intended product [Japanese Laid-Open Patent Publication Nos. 224043/1995, 224044/1995 and 198853/1996] (prior art 3).
A method of producing hexahydropyridazine which comprises synthesizing tetrahydropyridazine from 1,4-butanedial and hydrazine and hydrogenating this tetrahydropyridazine is also known [Japanese Laid-Open Patent Publication No. 109170/1996] (prior art 4).
As a method for producing tetrahydropyridazine from 1-aminopyrrolidine, there is known a method comprising carrying out a rearrangement reaction of diazenehydrazone on silica or alumina in, for example, a chloroform-methanol solvent [Tetrahedoron Letters, No. 52, pp. 5025 to 5026] (prior art 5). Furthermore, a method comprising leaving 1-aminopyrrolidine to stand at room temperature in chloroform for 2 weeks is also known [Japanese Laid-Open Patent Publication No. 250388/1989], [Chem. Ber., 109, (11), 3707 (1976)] (prior art 6).
However, the prior art 3 relating to a method for producing hexahydropyridazine has a problem that the dihalogenobutane as a starting material is economically expensive, and the synthetic route up to the product is long.
On the other hand, in the prior art 4, 1,4-butanedial used as a starting material is not easily available, and the yield is as low as about 60%.
Furthermore, the prior art 5 relating to a method for producing tetrahydropyridazine conducts a oxidation and rearrangement reaction of the starting material while it is adsorbed on silica or alumina. However, the after-treatment after the reaction is complicated. Furthermore, in the prior art 6, the reaction time is long, and it is inadequate as an industrial method for producing tetrahydropyridazine.